Tampon package and method for making same

ABSTRACT

A sealed tampon package and continuous process for making the package. Heat seals, preferably hermetic longitudinal and cross seals, are preferably peelable. The tampon is sealed under sufficient negative pressure to snugly retain the tampon in place without crushing or misshaping the tampon, yet without bursting the package under normal external pressures realized during storage. The tampon package will remain sealed during normal wear and tear, yet is easily opened when desired by peeling the seals.

BACKGROUND OF THE INVENTION

The invention relates to a tampon package. More specifically, theinvention is directed to a hermetically sealed, moisture-proof, peelablepackage for storing tampons and for ease of opening.

Tampons are commonly packaged using a paper wrapping. Such wraps allowair and moisture to seep through and contaminate the tampon.

It is also known to package tampons in plastic. However, known packagesuse positive pressure. If pressure is applied to the tampon, the packagecan burst open. Such packages also may use perforated ends which canwear apart over time.

Accordingly, it would be advantageous, and it is an object of theinvention to provide: a tampon package which is sealed in a negativeatmosphere to prevent bursting of the package from external pressure;which provides a hermetically sealed, moisture-proof package; and whichprovides a peelable package whose openings will not wear open over areasonable storage time.

It would also be advantageous, and is another object of the invention,to provide a continuous process for packaging tampons in this manner.

DEFINITION OF CLAIM TERMS

The following terms are used in the claims of the patent as filed andare intended to have their broadest meaning consistent with therequirements of law.

“Hermetic seal” or “hermetically sealed” means a seal that will excludeair and will be leakproof at normal temperatures and atmosphericpressure to the extent the thermoplastic materials used permit.

“Peelable” refers to a seal which may be readily manually broken by aconsumer.

Where alternative meanings are possible, the broadest meaning isintended. All words used in the claims are intended to be used in thenormal, customary usage of grammar and the English language.

SUMMARY OF THE INVENTION

The objects mentioned above, as well as other objects, are solved by thepresent invention, which overcomes disadvantages of prior art packagesand packaging methods, while provided new advantages not previouslyobtainable.

In one embodiment of the present invention, a sealed tampon package isprovided using a length of thermoplastic material entirely enclosing thetampon and formed into a wrapper. The wrapper may include top and bottomweb portions. The bottom web portion may be comprised of an extensible,thermoformed material. The wrapper preferably includes two opposedlongitudinal seals formed along its length and two opposed cross-seals.These seals may be heat seals, and preferably are hermetic heat seals.The seals may be formed by applying pressure at sealing zones located atopposed edges on the package and heating the sealing zones to atemperature and for a time sufficient to form longitudinal and crossseals that are hermetic around the entire periphery of the package. Thehermetically sealed, individually wrapped tampon is under negativepressure, such as in the range of 8–20 inches of Mercury, and morepreferably in the range of 10–15 inches of Mercury, in an amountsufficient to retain the tampon snugly within the package withoutcrushing or misshaping the tampon. At least one of the cross-sealsand/or the longitudinal seals is peelable, preferably withoutdelamination of the thermoplastic material. The peelable sealspreferably have a peel strength in the range of 600–800 grams/inch ofwidth.

Various alternative film materials may be manufactured and formulatedfor use as the package material. For example, the thermoplastic film mayconsist of an extruded film, or a solution cast or calendered material.Further, the top web portion may be made of a linear low densitypolyethylene material comprising an ethylene vinylacetate/polyisobutylene blend, while the bottom web portion may be madeof a nylon/low density polyethylene blend.

In an alternative embodiment, the cross-seals may include one or morenotches to facilitate opening of the package. Tear tape may also be usedto facilitate package opening.

In another embodiment, the package may include a flow-through stylewrapper in which negative pressure on the tampon is provided using a gasflush technique.

In another preferred embodiment, the invention consists of a continuousprocess for hermetically packaging a tampon, in which a continuous webof heat-sealable thermoplastic material is formed into a first wrapperwhich entirely encloses the tampon. As the web is continuously moved ina forward direction, portions of the web periphery surrounding thetampon are heated and pressured in a sufficient amount to form hermeticlongitudinal and cross seals so that the tampon is entirely surroundedby the hermetically sealed plastic web to form a hermetically sealedpackage. The hermetic seals are formed in a continuous manner as the webis moved forward, and are peelable. Negative pressure is applied to thetampon within the package in the range of about 8–20 inches of Mercury.Negative pressure may be applied using a gas flush technique.Preferably, the peel strength of the peelable seals is in the range of600–800 grams/inch of width.

In an alternative embodiment, the tampon may first be packaged in asecond, inner wrapper, which may be made of a paper-based material,prior to being packaged within the first wrapper.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features which are characteristic of the invention are setforth in the appended claims. The invention itself, however, togetherwith further objects and attendant advantages thereof, will be bestunderstood by reference to the following description taken in connectionwith the accompanying drawings, in which:

FIGS. 1—4 are side perspective views of various embodiments of thetampon package invention; and

FIG. 5 is a sectional view along reference line 5—5 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Set forth below is a description of what is currently believed to be thepreferred embodiment and/or best example of the invention claimed.Future and present alternatives and modifications to this preferredembodiment are contemplated. Any alternatives or modifications whichmake insubstantial changes in function, in purpose, in structure or inresult are intended to be covered by the claims of this patent.

In accordance with a preferred embodiment of the invention, a packagedtampon, generally referred to as 10, is shown in FIG. 1. Package 10preferably incorporates the advantages of the invention described above,and may include an extensible, thermoformed, longitudinal bottom web 15designed to snugly hug the tampon, a top web 17 which forms the opposinglongitudinal side of the package, and opposing ends 20, 21. One of thewebs, preferably the top web, may be colorized if desired. A peelableheat seal, preferably a hermetic seal, may be provided. Use of hermeticlongitudinal seals 25 and hermetic cross-seals 26 will insure that thetampon is entirely, hermetically enclosed within the package.

“Peelable” refers to a seal which may be readily, manually broken by theconsumer; preferably no rupturing or tearing of the film occurs duringpeeling, though this is not a requirement of the invention. Unsealedopposing flaps 20A, 20B may be provided at one end of the package tofacilitate peeling open the heat sealed package. At least one of thecross-seals and/or the longitudinal seals is preferably peelable withoutdelamination of the thermoplastic material. A seal may also be providedwhich is peelable by delaminating layers of film in a lamination, i.e.,the bond strengths in the lamination are designed to give way whensubjected to peel force. Preferably, the opposing ends intersect in ahermetic seal which is sufficiently strong so that mere storage, normalhandling or the passage of time will not wear away the seal and cause itto unintentionally open. The hermetic seal may be adhesive (i.e.,referring to a seal failure mode in which a film sealant layer(s)separate from a base or substrate film layer) or cohesive (i.e.,referring to a seal failure mode in which portions of a film sealantlayer(s) separate from itself/themselves) in nature. Cohesive failurepeel seals may be created using polyisobutylene, which prevents theplastics at the sealing interfaces from tightly commingling and allowsthem to peel apart without tearing film. Cohesive seals may, whenpeeled, leave a discoloration, which may or may not be desirable. Thehermetic seal preferably falls within the following negative pressureranges: 8–20, and more preferably 10–15, inches of Mercury as determinedthrough visual observation in a bell jar. Preferably, the tampon issealed in a negative atmosphere sufficient to prevent bursting of thepackage from external pressure, and also sufficient to maintain ahermetic seal, yet not so strong as to constrict or misshape the tampon.23–25 inches of Mercury was determined to be excessive negative pressurewhich crushed the tampon. The peel strength of the heat seals ispreferably in the range of 600–800 grams/inch of width.

In an alternative embodiment, an easy-open feature may be provided.Thus, as shown in FIG. 2, Zip opening tear tape 32 may be employed tofacilitate opening of package 10. One or more tear notches may be alsobe provided, as shown in FIG. 3, designed to tear linearly, and may beused with or without tear tape.

In yet another alternative embodiment, a flow-through style wrapperusing vacuum or gas flush may be provided. For example, anitrogen-carbon dioxide gas mixture may be introduced into the tube,such that as the carbon dioxide escapes from the film (the nitrogen,with its larger molecules, will do so more slowly over time), the filmwill fit snugly against the tampon. The degree of snugness can bemodified given the gas mixture and the film permeation rates.

Alternatively, as shown in FIG. 4, the tampon 12 may be packaged in apaper, “inner” wrapper 40, which is then packaged in a plastic “outer”wrapper as described above. The inner wrapper is not a necessary part ofthe invention, however.

One film material 50 suitable for forming a top web and providing apeelable seal is 48 BOPet (biaxially oriented polyester) adhesive, 2mil. LLDPE (linear low density polyethylene, EVA (ethylene vinylacetate)-PIB (polyisobutylene) blend), coextrusion. EVA/PIB blend isused to provide peel seal properties. Other suitable films for forming atop web and providing a peelable seal include:

-   -   48 BOPet/7#LDPE/1.5 mil LLDPE (EVA-PIB blend) coextrusion, where        LDPE is low density polyethylene    -   60 BON/adhesive/2 mil LLDPE (EVA-PIB blend) coextrusion, where        BON is biaxially oriented nylon    -   60 BON/7# LDPE/1.5 mil. LLDPE (EVA-PIB blend) coextrusion    -   80 BOPP/adhesive/2 mil. LLDPE (EVA-PIB blend) coextrusion, where        BOPP is biaxially oriented polypropylene    -   80 BOPP/7# LDPE/1.5 mil. LLDPE (EVA-PIB blend) coextrusion        A thermoformable bottom web may be provided using one of these        films, for example:    -   3–3.5 mil. Nylon/tie/LLDPE coextrusion    -   2–2.5 mil. Nylon/adhesive/1 mil. LLDPE    -   2–2.5 mil. formable PET/adhesive/1 mil. LLDPE, where PET is        polyester.

While non-oriented substrate film layers are currently preferred (toavoid additional film processing steps, and also because cast films tendto be lower cost), there may be some advantage in a particularapplication to using an oriented film, which may be stronger than anon-oriented film.

Various additives may be provided to the film for different purposes.Processing aids such as slip and antiblock additives may also be used asneeded. Slip or coefficient of friction (COF), the measure of how easilyor difficult a film surface slips upon itself. Typically, films withCOFs in the range of 0.1 to 0.3 (high to medium slip) are suitable forhigh speed automatic wrapping machines.

Of course, those of ordinary skill in the art will realize that otherfilm formulations can be used to accomplish the general objectives ofthe present invention. Potential film substrates may includepolyethylene and its variants (such as EVA (ethylene vinyl acetate), EMA(ethylene methyl acrylate), EEA (ethylene ethyl acrylate), HDPE, LDPE,LLDPE, linear LDPE, and metallocene polyethylenes), polypropylene,paper, nylon, cellophane, polyester, aluminum foil, polystyrene oracrylonitriles. Potential sealant layer compositions may includepolyethylene and its variants, as well as waxes and other food-safeadhesives or coatings such as ionomers, polybutylene, acid-modified EVA,EMA, tackifiers such as terpenes, synthetic waxes and polyisobutylene.

Film processing techniques that can be utilized to provide packagingfilms useful with the present invention include, but are not limited to,extrusion, coextrusion, extrusion coating, lamination and drylamination, for example.

It will be understood by those of ordinary skill in the art that theefficacy of a heat seal is a function of dwell time, sealing temperatureand sealing pressure. It will also be understood that the particulars ofsuch time, temperature and pressure will vary depending upon suchvariables as the film selected, the desired speed, the food itemselected, the sealing equipment used, and the desired seal character.

Persons of ordinary skill in the art will understand that, typically,packages of the present invention will be made using a horizontalthermoform machine, as well known in the art. However, it is alsounderstood that the present invention may be adapted for use withvertical fill-and-form machines, as well.

Those of ordinary skill in the art will appreciate that the parametersinvolved in food packages may differ from non-food packages in somerespects. Food packages generally require low oxygen and moisturepermeation rates, i.e., 1 cc or less of oxygen per 100 sq. inches/24hours, and 1 gram or less of moisture per 100 sq. inches/24 hours.Hermetically sealed food packages are an obvious preference to maintainlow oxygen and moisture quantities within the package throughout itshandling and distribution cycle. Hermetic seals provide sanitaryadvantages for tampon packaging, as well. Direct contact food packagingmaterials must meet FDA regulations spelled out in Rule 21 of the Codeof Federal Regulations. Finally, the design of food packaging equipmentmust incorporate features to minimize potential for food contamination,i.e., stainless steel food contact surfaces and disassembling featuresto assure effective cleaning.

The above description is not intended to limit the meaning of the wordsused in the following claims that define the invention. Rather, it iscontemplated that future modifications in structure, function or resultwill exist that are not substantial changes and that all suchinsubstantial changes in what is claimed are intended to be covered bythe claims.

1. A hermetically sealed, moisture-proof tampon package which resistsinadvertent opening and maintains the package integrity, therebypreventing damage and contamination to the tampon, comprising: a lengthof thermoplastic material entirely enclosing the tampon, thethermoplastic material formed into a flexible wrapper; the wrapperhaving two opposed hermetic longitudinal seals formed along its lengthand two opposed hermetic cross-seals, the seals being formed by applyingpressure at sealing zones located at opposed edges on the package andheating the sealing zones to a temperature and for a time sufficient toform longitudinal and cross seals that are hermetic around the entireperiphery of the package; wherein a hermetically sealed individuallywrapped tampon is produced which is under negative pressure sufficientto retain the tampon snugly within the package without crushing ormisshaping the tampon; and wherein at least one of the cross-seals andthe longitudinal seals are manually peelable.
 2. The tampon package ofclaim 1, wherein the seals are peelable without delamination of thethermoplastic material.
 3. The tampon package of claim 1, wherein thenegative pressure is in the range of 8–20 inches of Mercury.
 4. Thetampon package of claim 3, wherein the negative pressure is in the rangeof 10–15 inches of Mercury.
 5. The tampon package of claim 1 wherein thepeelable seals have a peel strength in the range of 600–800 grams/inchof width.
 6. The tampon package of claim 1, wherein the wrappercomprises top and bottom web portions, wherein the bottom web portioncomprises an extensible, thermoformed material.
 7. The tampon package ofclaim 6, wherein the top web portion comprises a linear low densitypolyethylene material comprising an ethylene vinylacetate/polyisobutylene blend.
 8. The tampon package of claim 6, whereinthe bottom web portion comprises a nylon/low density polyethylene blend.9. The tampon package of claim 1 wherein at least one of the cross-sealsincludes one or more notches to facilitate opening of the package. 10.The tampon package of claim 1,the package further comprising tear tapeto facilitate its opening.
 11. The tampon package of claim 1, wherein atleast one of the longitudinal sides of the package comprises anextensible, thermoformed plastic material.
 12. The tampon package ofclaim 1, wherein the package comprises a flow-through wrapper andnegative pressure is provided using a gas flush technique.
 13. Thetampon package of claim 1, wherein the thermoplastic film comprises anextruded film.
 14. The tampon package of claim 1, wherein thethermoplastic film comprises a solution cast or calendered material. 15.A sealed, moisture-proof tampon package which resists inadvertentopening and maintains the package integrity, thereby preventing damageand contamination to the tampon, comprising: a length of thermoplasticmaterial entirely enclosing the tampon, the thermoplastic materialformed into a flexible wrapper; the wrapper having two opposedlongitudinal heat seals formed along its length and two opposedcross-seals comprising heat seals, the heat seals being formed byapplying pressure at sealing zones located at opposed edges on thepackage and heating the sealing zones to a temperature and for a timesufficient to form longitudinal and cross heat seals around the entireperiphery of the package; wherein a heat sealed individually wrappedtampon is produced which is under negative pressure sufficient to retainthe tampon snugly within the package and to cause the package tosubstantially conform to the shape of the tampon without crushing ormisshaping the tampon; and wherein at least one of the cross-seals andthe longitudinal seals is manually peelable.